Direction Interrégionale de LA REUNION
B.P.4    97491 Ste Clotilde Cedex
Téléphone                02.62.92.11.00
Fax exploitation      02.62.92.11.48
Fax direction           02.62.92.11.47

RSMC / TROPICAL CYCLONE CENTRE / LA REUNION TROPICAL CYCLONE FORECAST WARNING (SOUTH-WEST INDIAN OCEAN) 0.A WARNING NUMBER : 11/12/20082009 1.A OVERLAND DEPRESSION 12 (EX-JADE) 2.A POSITION 2009/04/06 AT 1800 UTC : 17.9S / 48.8E (SEVENTEEN DECIMAL NINE DEGREES SOUTH AND FORTY EIGHT DECIMAL EIGHT DEGREES EAST) MOVEMENT : SOUTH-SOUTH-WEST 12 KT 3.A DVORAK ANALYSIS : / 4.A CENTRAL PRESSURE : 5.A MAX AVERAGE WIND SPEED (10 MN) : 40 KT RADIUS OF MAXIMUM WINDS (RMW) : NIL 6.A EXTENSION OF WINDS BY QUADRANTS (KM): 30 KT NE: 300 SE: 300 SO: NO: 7.A FIRST CLOSED ISOBARE (PRESSURE / AVERAGE DIAM): 1008 HPA / 800 KM 8.A VERTICAL EXTENSION OF CYCLONE CIRCULATION: DEEP 1.B FORECASTS: 12H: 2009/04/07 06 UTC: 19.8S/48.4E, MAX WIND=030KT, OVERLAND. 24H: 2009/04/07 18 UTC: 21.3S/48.0E, MAX WIND=030KT, OVERLAND. 36H: 2009/04/08 06 UTC: 22.4S/47.6E, MAX WIND=020KT, OVERLAND. 48H: 2009/04/08 18 UTC: 23.2S/47.3E, MAX WIND=020KT, DISSIPATING. 60H: 2009/04/09 06 UTC: 23.7S/47.2E, MAX WIND=015KT, DISSIPATING. 72H: 2009/04/09 18 UTC: 24.1S/47.0E, MAX WIND=015KT, DISSIPATING. 2.B OTHER INFORMATIONS: STEERED BY A NORTH-NORTHEASTERLY FLOW GIVEN BY THE MID LEVEL RIDGE LOCATED TO THE EAST (AROUND 60E), THE SYSTEM HAS TAKEN A MORE SOUTHWARDS COMPONENT WITHIN THE LAST HOURS. 12Z RUN SHOW A LESS SPREAD THAN THE 00Z RUN FOR THE TRACK FORECASTS. NGP STILL TRACKS THE SYSTEM ON WEDNESDAY NIGHT OFF THE SOUTHWESTERN COAST OF MADAGASCAR, BUT OTHER AVAILABLE MODELS ARE IN GOOD AGREEMENT WITH A SOUTHWARDS TRACK OVERLAND, ALONG THE EASTERN MALAGASY COAST. ECMWF/UKMO TRACK THE SYSTEM BACK OVER WATER OFF THE EASTERN MALAGASY COAST AT THE END OF THE WEEK. BEYOND RANGE 48H, THE SYSTEM SHOULD STRONGLY SLOW DOWN DUE TO THE NEW SUBTROPICAL HIGH. PRESENT FORECAST IS BASED ON A GLOBAL CONSENSUS OF ALL AVAILABLE NWP MODELS. ACCORDING TO THIS SCENARIO, THE SYSTEM STAYS OVERLAND AND COULD DISSIPATE WITHIN THE FORECAST PERIOD. HOWEVER IT IS IMPORTANT TO NOTICE THAT THERE IS A STRONGER THAN USUAL UNCERTAINTY ASSOCIATED WITH THE FORECAST TRACK. IT IS NOT UNLIKELY THAT THE SYSTEM COULD MOVE BACK OVER WATER WITHIN THE NEXT 72 HOURS OFF THE EASTERN COAST OF MADAGASCAR.